Musannaf Ibn Abi Shayba 33:428

Hafs ibn Ghiyath narrated to us, from ‘Amr ibn Maymun, from his father, who said: Ibn ‘Umar entered with some of his companions upon ‘Abdullah ibn ‘Amir ibn Kurayz while he was ill, visiting him. They said to him, "Rejoice, for you have dug the basins at ‘Arafat, from which the pilgrims to the House of Allah drink, and you have dug wells in the wilderness." They mentioned other qualities of goodness. They said, "We truly hope for good for you, if Allah wills." Ibn ‘Umar was sitting and not speaking. When the speech became prolonged for him, he said, "O Abu ‘Abd al-Rahman, what do you say?" He replied, "If the earning is pure, the expenditure is blessed, and you will return [to Allah] and then you will know."